GRAPTOLITES OE NEW YORK, PART 2 24 1 



the neighborhood of Amsterdam in the Mohawk valley, that are covered 

 with this form in surprising' multitudes and to the exclusion of all other 

 fossils. It was further found by the writer in the transition beds from the 

 Trenton limestone to the Utica shale along the shore; at Panton, \"t. ; and 

 also observed on the east shore of Green Island, opposite the city of Troy, 

 in association with D i p 1. foliaceus, C 1 i m. t y p i c a 1 i s and a mollusk 

 fauna which indicates the highest horizon of the Utica shale or an approach 

 to the Lorraine beds. The form cited in the above mentioned publication 

 as C. c u r t u s and as occurring at Mechanicville in association with 

 C 1 i m a c o g r. caudatus, etc. has here been made the type of a separate 

 variety (C . curtus van c o m m a). 



C. curtus can be said to ranoe in New York throughout the Avhole 

 Utica formation and to be characteristic of the same. A peculiarity of its 

 distribution in this formation is that, while it is a regular constituent of the 

 Utica shale fauna in the Hudson valley and still very common in the lower 

 Mohawk valley (Amsterdam, Sprakers Basin), it has not been observed at 

 all by the writer in the well searched Utica beds of the middle and upper 

 Mohawk valley and west of the Adirondacks. 



Lapworth records this species from the Hartfell shales in S. Scotland 

 and from County Down in Ireland. 



Remarks. The small size and graceful curvature of the rhabdosome 

 distinguish this form from others with the exception of the variety described 

 below, which is still shorter, more compact in appearance and more strongly 

 curved. The armature of the aperture is much reduced when compared 

 with the earlier forms, and altogether this form appears more primitive than 

 its predecessors. The sicula is missing in the great majority of the speci- 

 mens and seems to have been easily lost or been so thin, that it frequently 

 failed to be preserved in the rock. 



The thecae seem to have all originated in close proximity to the sicula, 

 but the first theca attained considerable size before the second and third 

 began to bud, for in numerous apparently unmutilated specimens only the 

 sicula and one, nearly full grown theca are observable. The same observa- 

 tion has been made in regard to C . fjrac i 1 i s. 



